Decimal storage and display unit



Dec. 13, 1960 s. GODET DECIMAL STORAGE AND DISPLAY UNIT 3 Sheets-Sheet 1Filed Dec. 27, 1956 IN V EN TOR. S/DNEY Gops'r @6 4 flTTORNEYS Dec. 13,1960 s. GQDET 2,9 4,742

DECIMAL STQRAGE AND DISPLAY UNIT Filed Dec.- 27, 1956 3 Sheets-Sheet 2INVENTOR. SIDNEY GQDET Dec. 13, 1960 s. GODET 2,964,742

DECIMAL STORAGEYAND DISPLAY UNIT Filed Dec. 27, 1956 s Sheets-Sheet 3T1r:1-1l.

EN'PG/ZED (1) f/vEPG/ZED O was 12:13

ENEPG/ZED INVENTOR. S/DA/EY @0251 BY @AW @614 Z #W United States PatentDECIMAL STORAGE ANDDISPLAY UNIT Sidney Godet, Great Neck, N.Y., assignorto Reeves Instrument Corporation, New York, N.Y., a corporation of NewYork Filed Dec. 27, 1956, Ser. No. 630,863

13 Claims. (Cl. 340--324) This invention relates to storage and displaydevices and more specifically to a novel and improved device responsiveto a coded decimal or binary system for visually displaying referencecharacters such as Arabic numerals.

In addition to displaying a numeral set up on the input lines, thedevice will retain the information after removal of power from the inputlines and will provide output signals corresponding to the storedinformation in binary form. Through the use of a number of these devicessimultaneous multi-digit numbers can be displayed.

One object of the invention is the provision of an improved displaydevice responsive to a coded decimal system for visually reproducingdigits 0 through 9 and at the same time storing information pertainingto the digit being displayed for the control of other apparatus.

Another object of the invention is to provide a decimal storage anddisplay device that is characterized by its simplicity, dependabilityand relatively low cost. Through an improved arrangement and combinationof elements the number of moving parts are reduced to a minimum and thedevice will respond substantially instantaneously to a given signal orset of signals representing or denoting the digit to be displayed.

The above and other objects of the invention will become more apparentfrom the following description and accompanying drawings forming part ofthis application.

In the drawings:

Fig. l is a plan view in section along the line 11 of Fig. 2 of adisplay device embodying the present invention;

Fig. 2 is a side elevational view of the apparatus shown in Fig. 1 insection along the line 2-2 thereof;

Fig. 3 is a cross-sectional view of the apparatus shown in Fig. 1 takenalong the line 33 thereof;

Fig. 4 is a bottom view of the portion of the apparatus shown in Fig. 3;

Fig. 5 is a cross-sectional view of the apparatus shown in Fig. 1 takenalong the line 55 thereof;

Fig. 6 is a perspective view of the rotary solenoid armature and rotarymirror shown in the cross-sectional view of Fig. 5;

Fig. 7 is a diagrammatic view of the solenoid stator shown in Fig. 5with the wiring connections thereto;

Figs. 8, 8a, 9, and 9a are diagrammatic illustrations of portions of therotary solenoid illustrating the organization of elements and operationthereof;

Fig. 10 is a circuit diagram illustrating the operation of the deviceshown in Figs. 1 through 9a, inclusive; and

Fig. 11 is a chart illustrating one binary system and the manner inwhich the apparatus illustrated is operated to attain the desiredresults.

Broadly, the invention provides an improved device embodying an opticalsystem having four moving elements arranged and coordinated to providefor the optical display of ten digits. It is actuated by coded data inthe form of four voltages that are either present or absent in fourseparate circuits. Each of the circuits controls the operation of one ofthe moving elements so that 2,964,742 Patented Dec. 13, 1960 selectedoperation of the moving elements will function to project a visiblereproduction or image of the selected number or digit.

In the illustrated embodiment of the invention, the four individualsolenoid units are associated with the numbers 1, 2, 4, and 8,combinations of which can be used to reproduce all of the digits 1through 9. For instance, the digit 3 can be obtained by energizing thesolenoid units associated with the numbers 1 and 2. The digit 7 can beproduced by energizing the solenoid units associated with the numbers 1,2, and 4. 0 is produced when all the solenoid units are deenergized. Itis to be understood that while the foregoing binary system was selectedfor use in connection with the illustrated embodiment of the invention,any other suitable system may be used.

The storage feature on this invention is preferably obtained bymechanically coupling electric switches with each of the four movingelements so that actuation of selected moving elements to reproduce agiven digit will actuate the associated switches to store the binaryinformation in any suitable and well-known manner. Through theutilization of an improved rotary solenoid forming the actuating meansfor the moving elements, a single clearing signal may be applied to allof the elements after display of a selected digit and prior to thetransmission of a new set of signals for the display of a new digit orset of digits.

Referring to the drawings, there is illustrated a single display unitwhich includes a housing 10 having substantially parallel side walls 11and 12 and contoured upper and lower surfaces, the latter functioningnot only to enclose the optical elements within the housing, but also aspart of the optical system as will be described.

The four moving elements of the optical system for the selection of thedigit or character to be displayed by the apparatus are generallydenoted by the letters A through D, inclusive. The element A includes atwo position rotary solenoid 13 mounted on the outside of the side wall11 for the operation of a mirror 14 disposed within the housing. Theelement B includes a two position rotary solenoid 15 and an associatedmirror 16 disposed within the housing as in the case of the mirror 14.The axis of rotation of the mirrors 14 and 16 are disposed transverselyof the housing and in this embodiment of the invention are in ahorizontal plane. The element C which is similar to elements A and B,includes a two position rotary solenoid l7 and a mirror 18 coupledthereto. The mirror 18 rotates about an axis in a vertical plane and ispositioned adjacent a projector lens 19 mounted in the right-hand end ofthe housing 10. The fourth moving element D also includes a two positionrotary solenoid 20 which is similar to the solenoids used in connectionwith the other elements and is disposed at one end of a rotatableturnstile-like member 21 having four elongated opaque panels 22 spacedat intervals about and extending from a central supporting shaft 23. Thepanels 22 disposed in one plane carry the numerals 1, 5, 9, 0, 4, 8 asillustrated in Fig. 2, while the panel 22 disposed in a planeperpendicular to the first panels, carry the numerals 3, 7, 2, and 6.The numerals or other characters on the elongated panels 22 may beformed of translucent or transparent material or they may be formed byopenings in the panels 22 to permit the passage of light therethrough.In the present embodiment of the invention, the numerals or digits onthe turnstile 21 are illustrated as being illuminated by a suitablelight source such as the lamps 24 disposed at the lefth-and portion ofthe housing 10, as shown in Figs. 1 and 2. However, it will beunderstood that any suitable procedure or struc ture may be used forilluminating the characters to be displayed.

, In addition to the elements of the optical system referred to above,the upper wall of the housing includes an inclined section 25 having areflecting surface on the inner side thereof. The top of the housingfurther includes a horizontal surface 26 for mounting the solenoid 20and providing a bearing'surface for the turnstile 21 and a lowerhorizontal portion 27 on which the solenoid 17 driving the mirror 18 ismounted. The lower wall of the housing includes an inclined portion 28having a reflector surface on the inside thereof. The lower end of theinclined portion 28 joins with a horizontal portion 29 which providesthe bottom bearing surface for the turnstile member. The upper end ofthe inclined wall part 28 terminates in a substantially vertical portion30 which joins with a horizontal portion 31 that provides the lowerbearing for the mirror 18. A vertically disposed end piece 32 extendsbetween the horizontal portions 27 and 31 at the right-hand end of thehousing and carries a suitable objective lens 19.

Two additional reflecting surfaces denoted by the numerals 33 and 34 areformed on the inner surface of the right-hand ends of the side walls 11and 12 as may be observed in Fig. 1. The ends of these side walls arebent inwardly at angles of approximately 45 and terminate short of theobjective lens 19 so that they will not block the transmission of lightthrough the lens. Another set of reflecting surfaces denoted by thenumerals 35 and 36 are positioned approximately midway between theturnstile member 21 and the objective lens 19. The reflecting surfaces35 and 36 are each aligned with one of the numerals at the center of thepanel 22 and may be formed by tabs partially cut from the side walls 11and 12 and bent inwardly to form incline surfaces at angles of 45 withrespect to the vertical axis of the turnstile 22.

As will be seen best from Fig. 2, light rays emanating from the numeralson the turnstile panels are deflected and directed toward the reflectingsurfaces 33 and 34 adjacent the lens by means of the reflecting surfaceson the inclined walls 25 and 28, and the tabs 35 and 36 in conjunctionwith the mirrors 14 and 16. As will now be explained, the position ofthe mirrors 14 and 16 will determine the particular horizontal pair ofnumerals which will be projected to the reflecting surfaces 33 and 34.In general, the reflecting surfaces are inclined at approximately 45 tothe light rays striking them and thus the reflected light rays will bedeflected at approximately 90 from the incident light rays.

Specifically, the light rays from the top pair of numerals (three andtwo or one and zero) will first strike the reflecting surface of theinclined wall 25 and be deflected downward to the mirror 14. The mirror14 deflects the light rays toward a lower point on the reflectingsurface of the inclined wall 25 which in turn deflects the light raysdownward to the mirror 16 and the mirror 16 will deflect the light raystoward the reflecting surfaces 34 and 33.

If the mirror 14 is shifted 90 (to the dot and dash line position),light from the top pair of numerals is cut oif at this point and lightrays from the middle pair of numerals (seven and six or five and four)will strike the reflective surfaces on the inclined tabs 35 and 36 andbe deflected upwardly to the reflective surface of the mirror 14. Themirror 14 again deflects these light rays toward the reflecting surfaceon the inclined wall 25 which in turn deflects the light rays to themirror 16. The mirror 16 then deflects the light rays to the reflectingsurfaces 33 and 34 as it did previously. Hence, the shift from the toppair of numerals to the middle pair of numerals is controlled by theposition of the mirror 14.

When the reflecting surface mirror 16 is shifted 90 (to the dot and dashline position), the light rays from the top and middle rows of numeralsare cut off and the light rays from the lower pair of numerals (nine andeight) will be directed toward the reflecting surfaces 33 and 34. Inthis case, the light rays from the lower pair of numerals strike thereflecting surface on the inclined wall 28 of the housing and aredeflected upwardly toward the mirror 16 and thence to the reflectingsurfaces 33 and 34. V

As will be seen best from Fig. 1, the position of the mirror 18 controlsthe projection of either the left or right hand numeral of the pair ofnumerals to the lens 19. For example, when light rays from thereflecting surface 34 strike the reflecting surface of the mirror 18,the rays will be deflected by the mirror toward the lens while lightrays from the other reflective surface 33 are cut off. When thereflective surface of the mirror 18 is shifted (to the dot and dash lineposition), the light rays from the reflecting surface 33 are deflectedby the mirror toward the lens 19 and the light rays from the reflectingsurface 34 are cut 011.

From the above it will be observed that by positioning of the turnstile21 and the three reflecting mirrors 14, 16, and 18, any one of the tennumerals may be selected for projection to the objective lens 19. Ifdesired, a series of numerals can be projected simultaneously by the useof a number of the devices positioned side by side.

The positions of the turnstile 21 and the mirrors 14, 16, and 18 arecontrolled by the two position rotary solenoids 13, 15, 17, and 20. Therotary solenoids are all identical in structure and therefore only oneof the solenoids need be described in detail. As shown in Fig. 5, theoperable elements of the solenoid 17 are contained within an outergenerally circular housing 37 that is preferably of a magnetic material.A pair of armatures 38 and 39 are fixedly secured to a central shaft 40rotatably mounted within the housing 37 and extending therefrom to carrythe operable element such as the mirror 18 or in the cases of the othersolenoids the mirrors 14 and 16 and the turnstile member 21.

The armatures 38 and 39 are arranged in spaced relationship and arepreferably angularly displaced with relation to each other. In theillustrated embodiment of the invention, the armatures are displaced byan angle of about 30 degrees (see Fig. 6). The field structures for thearmatures 38 and 39 comprise a pair of pole pieces 41 and 42 associatedwith the armature 39 and a second pair of pole pieces 43 and 44associated with the armature 38. The arrangement and disposition of thepole pieces 41 through 44 is shown more clearly in Fig. 7. The polepieces in this embodiment of the invention have arcuate lengths of 90degrees and are provided with coils or windings denoted by the numerals41a to 44a, inclusive. The pole pieces 41 and 42 comprise the stator forthe armature 39 and are magnetically coupled to the casing 37 so thatwhen the respective coils 41a and 42a are energized either in series orparallel, a magnetic field will be generated therebetween. The polepieces 43 and 44 comprising the stator for the armature 38 are offsetfrom the pole pieces 41 and 42 and also utilize the casing 37 as part ofthe magnetic circuit.

As will be shown, energization of the stator associated with onearmature will function to rotate the shaft 40 in one direction whileenergization of the stator associated with the other armature willfunction to rotate the shaft 40 in the opposite direction. In order toinsure precise movement of the shaft 40 through an angle of 90 degrees,a toggle spring assembly, generally denoted by the numeral 45, isutilized to cooperate with the solenoid to attain this end. The bottomview of the turnstile assembly, as shown in Fig. 4, will serve toillustrate the structure and operation of this toggle control. Thebottom end of the shaft 23 of the turnstile 21 includes a pair ofoutwardly extending arms 46 and 47. A tab or post 48 is secured to andextends from the bottom part 29 of the casing 10 and is disposed at apoint in alignment with the arms 46 and 47 when the turnstile ispositioned at a point midway of its throw and at the side of the arm 47.A spring 49 is connected between the arm 46 and the post or stud 48 sothat movement of the arm 46 from a position on one side of centerthrough the center position will enable the spring to cause .thearmtocontinue its movement to its other end position. By reason of thistoggle action,,the driving solenoid need only effect rotation slightlypast the center position when going in either direction, whereupon theaction of the spring 49 will complete the rotation. Rotation ofprecisely 90 degrees is controlled by a pair of stops 50 and 51 whichcooperate with the arm 47.

In order to store information fed to the driving solenoids or for thepurpose of control of other equipment, each arm 47 is provided with ashort extension 47 for actuating a suitable micro switch 52. With thisarrangement, when thearm 47 is in one position, the switch 52 is closedwhile in the other position of the arm 47 the switch is open. Thus,either momentary or continuous energization of certain of the solenoidsto display a given character or digit will function to actuate theassociated switches. By connecting each of the four switches to suitableapparatus (not shown), information indicating the numeral represented bythe information fed to the display device may be transmitted to suchapparatus.

The relay casings 37 which include the stator structure may be securedto the wall of the casing 10 in any suitable manner as, for instance, bytabs 37', as shown in Fig. 5. The shafts 40 for the several mirrors andshaft 23 for the turnstile are preferably supported by the walls of thecasing, although separate bearing structures may be provided for thispurpose if desired.

In order to illustrate more clearly the operation of the rotarysolenoids, the two positions of eachof the armatures 38 and 39 relativetotheir associated pole pieces are shown in Figs. 8, 8a, 9, and 90.

As was pointed out above, each of the pole pieces 41 to 44 comprise 90degree segments with reference to the center of rotation of thearmatures 38 and 39. In addition, the arcuate length of the pole faces38 and 39 of the armatures 38 andf39 are approximately 60 degrees asmeasured from the center of rotation. In the counterclockwise positionof the armature 39, as shown in Fig. 8, it will be observed that theleading edges a and c of the faces 39 of the armature 39 are alignedwith the edges 41 and 42 of the pole pieces 41 and 42 forming part ofthe stator. With the armature in this position it is to be understoodthat the toggle spring 49 has moved the arm 47 against one of the stops50, 51 as previously described. In the corresponding position of thearmature 38, as shown in Fig. 9, it will be observed that the trailingedges b and d of the pole faces 38 of the armature 38 are in line withthe edges 43' and 44 of the stator pole pieces 43 and 44. Since thetrailing edges 1) and d of the armature 39 are spaced 30 degrees fromthe edges 41" and 42" of the poles 41 and 42, the armature 39 will movein a clockwise direction when the field coils-41a and 42a associatedwith the pole pieces 41 and 42 are energized momentarily. Positivemotion is imparted to the armature 39 by the stator until the points band d are in alignment with the edges 41 and 42 of the poles 41- and 42.Since the arcuate length of the armature pole faces is 60 degrees, thepositive clockwise movement imparted to the armature will beapproximately 60' degrees, at which time the magnetic effects of thepole pieces 41 and 42 will no longer function to rotate the armature 39.At this point the armature can be readily moved through the remainingangle of 30 degrees without moving the pole faces 39' from beneath thestator poles 41 and 42. The initial 60 degree clockwise motion impartedby the stator will function to move the arm 46 of the toggle assemblypast a dead center position and the spring will carry the armature 39from a position wherein the edges of the armature pole faces b and d arein alignment with the edges of the stator poles 41 and 42 to theposition shown in Fig. 8a wherein the edges of the armature poles a andc are in alignment with the edges 41" and 42" of the poles 41 and 42.

During the displacement of the armature 39 in a clockwise direction asdescribed in Figs. 8 and 8a, the armature 54 to 5 7 is the number ordigit to be presented. If, for

33 will have been moved from the position shown in Fig. 9 to theposition shown in Fig. 9a. The energization of the field coils 43a and44a associated with the stator poles 43 and 44 will function to move thearmature 38 in a counterclockwise direction from the position shown inFig. 9a. More specifically, energizing the poles 43 and 44 will move thearmature 38 in a counterclockwise direction through an angle of 60degrees, at which point the toggle spring 49 will take over and move thearmature to the position shown in Fig. 9. Thus, a relatively shortelectrical impulse applied to field coils for the respective statorswill effect clockwise or counterclockwise motion of the shaft 40. Ineither case, the rotation of the shaft will be precisely degrees and thesolenoids will function with either short electrical pulses orcontinuous signals.

The binary system for controlling the operation of the solenoids 13, 15,17, and 20 is illustrated in Figs. 10 and 11. The binary system selectedfor the operation of the display and storage device described aboveutilizes four individual circuits each of which represents some integralpower of two.

Referring now to Fig. 10, the leads projecting from the top of eachsolenoid A through D, inclusive, are coupled with the stator thatfunctions to move the solenoids in a clockwise direction as viewed inFig. 10. The leads extending from the bottom of each solenoid are usedto move them in a counterclockwise direction. One lead from the statorsof each solenoid is connected to the ground terminal 53.. The remainingleads extending from the upper side of each solenoid are connected tothe terminals 54 to 57, inclusive. The other lead extending from thebottom side of each solenoid is connected to the terminal 58 to which isapplied a clearing signal for returning the system to a zero position.For convenience, the solenoids A through D, inclusive, in Fig. 10 havebeen illustrated diagrammatically along with their associated switches52 actuated by varms 47 so that movement of a given solenoid willactuate a switch inorder to store the information applied to the system.

Specifically, the terminal 54 isassociated with the number 4 andapplication of energy between it and the ground terminal 53 functions tomove the solenoid A (13) in a clockwise direction.- The signal appliedto the. terminal 55 is associated 'with the number 8 and functions tomove the solenoidB, (15) in a clockwise direction. Similarly, the signalapplied to terminal 56 is associated with the numberl and functionsto.move the solenoid C (17) in a clockwise direction. The signal appliedto the terminal 57 is associated with the number 2 and functions to movethe solenoid D 20) in a clockwise direction. With this arrangement, thesum of thenumbers represented by the voltages at one or more of theterminals instance, voltages representing the numbers 1 and 2 arepresented, the digit that will be displayed by the device will be number3. If it is intended todisplay number 7, voltages will be applied to theterminals 54, S6, and 57 which represent the numbers 1, 2, and 4 whichtotal 7.

The chart in Fig. 11 illustrates the system utilized for attaining thedisplay of any given numeral from zero through 9. For example, if all ofthe units A through D are deenergized (in their counterclockwisepositions), the number that will be projected through the objective lens19 will be zero. Momentarily energizing the unit C associated with themirror 18 will produce the digit 1. If the unit D is energized and allother units are deenergized, the number indicated will be the numeral 2.If both units C and D are energized, the number indicated will be 3,etc. With the present embodiment of the invention it is possible toobtain the numerals 8 and 9 with two different arrangements of signalsinasmuch as it will.

be noted that once the mirror 16 is rotated to the clock-.

wise position shown in Fig. 2, movement of the mirror 14 in response tothe operation of the rotary solenoid forming part of unit A will have noeffect on the system. A similar situation applies to the blank spaces onthe turnstile below the numerals 6 and 7.

The arrangement described above will provide a dependable relatively lowcost device that will respond to a suitable binary code to projectimages such as the numerals through 9, inclusive, and may also be usedto store the information for use in controlling other apparatus ifdesired. By reason of the improved rotary solenoids, the system willrespond to signals in the form of momentary pulses or continuousvoltages. Similarly, the clearing signal applied to the terminal 58 maybe either a continuous or momentary signal and will function to bringall of the units A through D to their counterclockwise or zeropositions. Any unit being in the zero or counterclockwise position whenthe zero signal is applied will be unaffected by such clearing signal.It may also be noted that once a signal is applied to a unit or a numberof units in order to move them in a clockwise direction, subsequentapplication of another signal to such unit will not affect its position.In certain cases it is not necessary to apply a clearing signal beforepresenting the code for the display of a different digit. For instance,if the numeral 1 is being displayed and the binary code calls for thepresentation of the numeral 3 it would only be necessary to energize theunit D. However, for simplicity it may be desirable to clear the displaydevice each time a new numeral or digit is to be presented.

In illustrating the invention, the switches 52 have been illustrated assingle-pole, single-throw devices though it is understood that othertypes of switches may be employed for operation by the rotary solenoidsA through D. Instead of operating electrical switches, the solenoidsmay, of course, be employed to operate other mechanical orelectromechanical devices as may be desired.

It should be noted that the lengths of the several light paths from lenselement 19 through the reflecting mirror system to each of the numeralson the turnstile panels 22 are identical. Thus, a focusing adjustmentfor lens 19 is unnecessary as the different numbers are projected by thedisplay unit.

The numerals 0-9 in Figs. 2 and 3 have been shown, for convenience, asappearing right side up. These numerals, however, would be projectedupside down upon a screen due to the optical inversion through lens 19.To project the numerals right side up, the display unit may be operatedin an inverted position.

It will be understood that various modifications, alterations andchanges may be made in the embodiment of the invention illustrated anddescribed herein without departing from the scope of the invention asdefined by the claims appended hereto.

I claim:

1. A display device comprising an objective lens, at least two groups oflight emitting characters, electromechanical means for positioning saidgroups of characters to emit light in the direction of said lens, aplurality of fixed reflectors and movable reflectors interposed in thepath of said emitted light and a plurality of electromechanicalpositioning devices each coupled to one of said movable reflectors forindividually positioning each of the movable reflectors in predeterminedpositions for presenting light from individual characters to said lenswhile blocking light from the other of said characters, saidelectromechanical devices being responsive to coded sets of electricsignals representing said characters.

2. A display device according to claim 1 wherein said electromechanicalpositioning devices coupled to each of the movable reflectors comprise atwo position rotary solenoid, said solenoid being rotatable in oppositedirections through an arc of predetermined magnitude.

3. A display device according to claim 1 wherein said groups ofcharacters are carried by panels disposed at right angles one to theother and movable through an angle of approximately 90 to position saidgroups individuallyw for the projection of light from selectedcharacters to said lens.

4. A display device responsive to coded binary electric signals foroptically displaying digits represented by said signals comprising aplurality of light emitting characters in the form of digits to bedisplayed, a lens spaced from said light emitting characters, fixedreflectors disposed between said characters and said lens, at leastthree rotatable reflectors each individually movable from one positionto another, and electromechanical positioning devices coupled to each ofsaid rotatable reflectors, said electromechanical positioning devicesbeing responsive to said signals for positioning said rotatablereflectors in positions where the light from a character represented bya coded signal is directed to said lens while light from othercharacters is blcckedfrom the lens.

5. A display device according to claim 4 wherein said charactersincluding the numbers 0 through 9 are carried on two panels disposed atright angles one to the other in the form of a rotatable turnstile andsaid device further includes electromechanical means for rotating saidturnstile in opposite directions in response to said coded signals, andsaid code includes at least four individual signals each applied to oneof said electromechanical devices and to said electromechanical meansrepresenting the digits 1, 2, 4, and 8 and a clearing signalrepresenting zero.

6. A display device according to claim 4 wherein said electromechanicalpositioning devices each comprises a rotary solenoid having a drivenshaft and toggle spring means coupled to the shaft, said solenoid beingmovable through a predetermined angle first in one direction and thenthe other in response to electrical signals applied thereto and thecooperating action of said toggle spring means.

7. A display device according to claim 4 including switch meansresponsive to said electromechanical means for storing said codedsignals.

8. A display device for optically displaying characters in response toan applied electric signal comprising in combination, an opaque panelmember having a plurality of transparent openings therethrough shapedaccording to the characters to be displayed, a light source situatedadjacent said panel member for passing light rays through each of theopenings in said panel member, fixed mirrors located in the paths ofeach of the groups of light rays passing through the openings in saidpanel member, said fixed mirrors being angularly inclined with respectto the light rays for reflecting the light rays passing through each ofthe openings in said panel member, a rotatable 2- position mirrorsituated in the reflected light paths of at least two of the charactersto be displayed and being angularly inclined with respect to thereflected light rays, electromechanical means coupled to said rotatablemirror and responsive to an applied signal for varying the angularposition of said rotatable mirror from a first angular position to asecond angular position, said rotatable 2- position mirror reflectinglight rays from one of the characters to be displayed when disposed insaid first angular position and reflecting another of said characterswhen disposed in said second angular position, and lens means situatedin the path of the light rays reflected from said rotatable 2 positionmirror for projecting said latter reflected light rays.

9. A display device for optically projecting a symbol selected from aplurality of illuminated symbols arranged in rows and columns comprisinga group of fixed row reflectors, each fixed row reflector being locateddirectly in the path of light rays from a corresponding row of saidilluminated symbols, a group of fixed column reflectors, each fixedcolumn reflector being located directly in the path of light rays from acorresponding column of said illuminated symbols, said fixed row andcolumn reflectors being angularly inclined -with respect to said lightrays, a group of first movable reflectors, one of said first movablereflectors being located between pairs of said fixed row and columnreflectors and adapted for selectively reflecting light from one or theother of said pairs of fixed row and column reflectors, a group ofangularly inclined secondary reflectors including at least one secondaryfixed reflector and at least one secondary movable reflector, each ofsaid secondary fixed reflectors being located directly in the path oflight from a movable reflector and each of said secondary movablereflectors being located between each of said fixed reflectors nothaving a first movable reflector receiving light directly therefrom, andlens means adapted to rece.ving light transmitted by said reflectorsfrom any of said illuminated symbols.

10. A selective display device for optically projecting a symbolselected from a group of illuminated symbols arranged in rows andcolumns, comprising a group of fixed row reflectors, each of said fixedrow reflectors being located in the path of light rays emanating from acorresponding row of said illuminated symbols, said fixed row reflectorsbeing angularly inclined with respect to said light rays, a pair ofangularly inclined fixed column reflectors, first and second movablereflectors, said first movable reflector being situated between a pairof fixed row reflectors, said second movable reflector being situatedbetween said pair of fixed column reflectors, said first and secondmovable reflectors being adapted for selectively reflecting light fromone or the other of said pair of fixed row reflectors and said pair offixed column reflectors respectively, an angularly inclined secondaryfixed reflector situated in the path of light reflected from said firstmovable reflector, a secondary movable reflector situated between saidsecondary fixed reflector and one of said fixed row reflectors, saidfixed column reflectors being situated in the path of light reflectedfrom said secondary movable reflector, and lens means situated in thepath of light reflected from said second movable reflector forprojecting one of said selected symbols.

11. A display device for selecting and optically projecting one of aplurality of symbols in response to a coded input signal comprisinghousing means, panel means mounted within said housing means, said panelmeans including a plurality of illuminated symbols, lens means spacedfrom said panel means, a plurality of fixed reflectors located withinsaid housing means between said panel means and said lens means, aplurality of individually movable reflectors located within said housingmeans between said panel means and said lens means, and a plurality ofelectromechanical positioning devices responsive to said coded inputsignal, each of said electromechanical positioning devices being coupledto one of said movable reflectors, said positioning devices positioningsaid movable reflectors to permit light rays from only the selectedsymbol to reach said lens means.

12. A display device as defined in claim 11 wherein the panel means isrotatable and which further comprises means for positioning said panelmeans in accordance with said coded input signal.

13. A display device as defined in claim 11 wherein said movablereflectors are rotatable and said plurality of positioning devicesindividually position each of said reflectors to either a first or asecond angular position in accordance with said coded input signal.

References Cited in the file of this patent UNITED STATES PATENTS1,893,158 Chireix Jan. 3, 1933 2,646,732 Ofleman July 28, 1953 2,738,450Matthews Mar. 13, 1956 2,767,628 Higonnet Oct. 23, 1956 2,779,016 ShellJan. 22, 1957 2,784,397 Branson Mar. 5, 1957 2,800,614 Thornbery July23, 1957 2,803,178 Lotz Aug. 20, 1957

